ABSTRACT - CORE D The Animal Imaging and Cytometry Core will support all Projects of the Program by providing key services, including: generation, breeding, and maintenance of genetically modified mouse colonies, murine asthma models (ovalbumin allergen, dust mite, and intratracheal IL-25 and in vivo NOS electroportion), mouse airway hyper-reactivity measures, processing and histological analyses of mouse lung tissues, murine data repository, in vivo-molecular imaging by Positron Emission Tomography (PET) and Single Photon Emission Computerized Tomography (SPECT) for iNOS activity and adherent cell cytometric analyses for intracellular probes. All required instruments and expertise are found in the Core. The Core expedites results and reduces cost of Projects through the use of shared model systems. New model systems and functional imaging increase overall innovation of the Program.